Transcriptional regulation of CrcZ and CrcY by RpoN.

A. Growth kinetic (circles) and acetate (triangles) or glucose (squares) consumption by the AErpoN (rpoN::Gm) strain cultivated in BAG-N medium. B. The activity of PcrcZ and PcrcY is RpoN-dependent. Strains AE-Zgus (PcrcZ-gusA) (wt) and AE-Ygus (PcrcY-gusA) (wt), and their respective rpoN::Gm derivatives (rpoN) were cultured in 25 mL of Burk’s medium amended with 30 mM acetate for 12 h, afterward 200 μg of protein derived from these pre-inoculums were used to inoculate 50 ml of BAG-N medium. Cells were harvested under acetate growing conditions (5h) and the activity of ß-glucuronidase (ß-Gluc) was determined. C. Quantification of CrcZ and CrcY transcripts by qRT-PCR analysis in the wild type strain AEIV (black bars) or in AErpoN strain (white bars). The total RNA was extracted from cells growing in diauxic BAG-N medium at the expense of acetate (5h). The bars of standard deviation from three independent experiments are shown. Significant differences were analyzed by t-test. Statistical significance is indicated (**p<0.01 or ***p<0.0001).